Image by aloshbennett used under the creative commons attribution license.

If someone we love smokes, we want them to quit. But we may not feel there's anything we can do about it. If we smoke, we probably know we need to quit, but may not feel we have the willpower to do it right now. (Though chances are, quitting's one of our New Year's resolutions.)

According to statistics kept by the Centers for Disease Control, about 23 percent of U.S. adults -- or almost one in four -- still smoke cigarettes despite years of public health warnings not to smoke.

From the caregiver's perspective, what really matters to us is that our loved ones live as long as possible, in as good a state of health as possible. In that spirit, here are a few things to think about when it comes to smoking and cancer.

1. Smoking increases the risk of all types of cancer, not just lung and throat cancer. It's a common misperception that if the lungs and throat seem to be tumor-free, then everything's hunky dory. Actually researchers now know that smoking causes mutations in our genes that can trigger colon cancer, breast cancer, skin cancer, prostate cancer, and many other types as well.

2. Some people are more susceptible to lung cancer than others. A genetic test can show whether you or someone you're concerned about has certain genes that increase susceptibility to cancer from smoking. This test is called genotyping; the genes they're looking for include IGF1 and IGF2 (insulin-like growth factor 1 and 2) and IGFBP3. Some hospitals, such as Massachusetts General, are now offering genetic testing to all lung cancer patients.

3. There are things smokers can do to protect themselves from cancer. This isn't to say that quitting smoking isn't important; it's definitely the best thing you or your loved one can do. But there are other things you can do that also give effective protection, though not as much, and these tend to be less talked about because the public health warnings focus on smoking.

• Drink green tea. This week researchers revealed the results of a study that showed that one cup or more a day of green tea appears to at least partially counter the effect of smoking on lung cancer. The researchers followed smokers and nonsmokers for five years and found that both smokers and nonsmokers who didn't drink green tea had more than five times the risk of lung cancer as those (smokers and non smokers) who had at least a cup of green tea a day. Among smokers, the non-green-tea drinkers had a nearly 13 times increased risk of lung cancer compared to the smokers who drank one cup or more of green tea per day. They also analyzed the study participants according to those who had the susceptible genotypes for lung cancer and those who didn't. Green tea was even more protective for those who didn't have one of the susceptible genotypes; they had a 66 percent reduced risk in lung cancer compared to the green tea drinkers who were susceptible. The takeaway is that while the best way to avoid lung cancer is to stop smoking, green tea appears to reduce risk for smokers.
• Eat a veggie diet. Just this week new reearch was published showing that saliva tests of current and former smokers revealed that those eating a diet high in green leafy vegetables and folate had fewer of the genetic changes associated with cancer risk.
• Take a genetic test to find out your risk. When a New Zealand-based company began offering a test called Respiragene last year, researchers discovered that smokers who took the test were more likely to quit after obtaining their results. Researchers announced that 40 percent of those who take the test attempt to quit afterward, as opposed to just 12 percent of smokers overall. If this is the motivation your or your loved one needs, go for it. Of course, the test, which you can order yourself, comes with a $700 price tag, so it's certainly cheaper simply to quit smoking on your own.

Keep in mind that smoking doesn't just cause cancer; it also leads to other serious health problems such as emphysema and COPD. So no one's saying it's okay to keep smoking if you're concerned about a family member's health or your own. But if a New Year's resolution to quit smoking is just not quite happening yet, in the meantime protect yourself by drinking green tea and eating your spinach and folate-fortified cereal.

And if you or a family member is or has been a smoker, talk to your doctor about having genetic testing to determine whether you carry genes that increase your lung cancer risk.